Is secondhand vape safe around a pregnant person?

What does the evidence say about secondhand vape exposure during pregnancy?

1. A case study of passive e-cigarette aerosol exposure in a family found detectable exposure biomarkers, including nicotine metabolites, in the cord blood of a fetus whose mother lived with an e-cigarette user despite not vaping herself. 1
2. E-cigarette aerosol exposure during pregnancy has been linked in research to reduced maternal uterine and fetal umbilical artery blood flow along with reduced fetal weight, effects the review notes closely resemble those seen with tobacco smoke exposure. 1
3. Secondhand exposure to burned tobacco smoke during pregnancy has consistently been shown to have a negative association with fetal growth, the established precedent that underlies why passive exposure to any inhaled aerosol, tobacco or otherwise, counts as a real prenatal exposure route rather than something to dismiss as harmless. 2
4. Real-world air measurements found that vaping raises ultrafine particle counts in a room substantially, and while a burning cigarette still produces far more particles overall, e-cigarette aerosol skews toward smaller, nano-sized particles, from 2 to nearly 3,800 times more of them at the smallest sizes measured, that penetrate deeper into the lungs. 3
5. Research on prenatal vaping exposure found metals including aluminum, chromium, nickel, copper, and lead crossing from a mother's system into fetal cord blood, along with dysregulated immune markers in exposed offspring, showing that aerosol-borne chemicals can reach a fetus even when levels in cord blood run lower than in the mother. 4

Is secondhand vape exposure safe in each trimester?

• First trimester. Passive exposure to nicotine and other e-cigarette aerosol components is worth minimizing from the start, since research on active e-cigarette exposure in pregnancy has found effects on blood flow to the developing placenta.
• Second trimester. The same guidance continues. If someone in your household vapes, asking them to step outside or use a separate, ventilated space reduces how much aerosol residue builds up indoors.
• Third trimester. Same precautions apply. Aerosol residue can also settle on surfaces and fabric (thirdhand exposure), so regular cleaning and airing out shared spaces helps if a household member vapes indoors.